package job;
import java.io.*;
import java.util.*;

//class Solution {
//    /* Write Code Here */
//    public double sqrSum(int n, int m) {
//        int count = 0;
//        double temp = n;
//        double sum = temp;
//        while(count < m - 1){
//            temp = Math.sqrt(temp);
//            sum += temp;
//            count ++;
//        }
//        return sum;
//    }
//}
//public class OnlineTest {
//    public static void main(String[] args){
//        Scanner in = new Scanner(System.in);
//        int n = 0;
//        int m = 0;
//        while(in.hasNextInt()){
//            n = in.nextInt();
//            m = in.nextInt();
//            Solution s = new Solution();
//            double c = s.sqrSum(n, m);
//            System.out.printf("%.02f", c);
//        }
//    }
//}




public class OnlineTest {
    public static void main(String[] args){
        int m;
        double sum, n;
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            n = in.nextInt();
            m = in.nextInt();
            sum = 0;
            for (int i = 0; i < m; i++){
                sum = sum +n;
                n = Math.sqrt(n);
            }
            System.out.printf("%.2f", sum);
            System.out.println();
        }
    }
}
